[Postpartum thyroiditis: current views on unappreciated disease]

Postpartum thyroiditis is a form of autoimmune thyroiditis developing during the first 12 months postpartum as a consequence of the immunologic flare following the immune suppression of pregnancy. This disease, found in 5-10% of women in a general population and even more frequently in patients suffering from other autoimmune disorders, may re-occur in about 70% of women after a subsequent pregnancy. Postpartum thyroiditis is strongly associated with antithyroid peroxidase antibodies. Patients may present with symptoms of either thyrotoxicosis or hypothyroidism which may be transient or, in some (20-30%) cases of hypothyroidism, permanent in nature. A thyrotoxic phase of postpartum thyroiditis is usually brief and often unnoticed before a more long-lasting hypothyroid phase occurs. The diagnosis of postpartum thyroiditis is based on the observation of abnormal thyroid function tests in a postpartum antithyroid peroxidase- positive woman. In this paper, we discuss the etiopathogenesis, clinical picture, diagnosis, prognosis and treatment of postpartum thyroiditis and provide the reader with some practical guidance concerning dealing with a patient suffering from this disorder.